Re: beam splitter quality

[P3D Michael Kersenbrock <michaelk@xxxxxxxxxxxxxxxxxx>]

> Thanks for everything I've read, whether directed to me personally or 
> to others--it has been invaluable in getting a very clear idea of the 
> parameters of stereo photgraphy, especially with beam splitters and 
> with actual stereo cameras.

The list of "features" were specified to be for "low cost" splitters.
The Pentax one (currently) is *NOT* a low cost one.  Mine was under
a hundred dollars, but that was a LONG time ago.  :-)

> How much better is the Pentax beam splitter than the Porter or the Reel 
> 3-D (Franka) in particular. I suppose it is made of metal, but does it 

Mostly plastic, but the cover that keeps dust (etc) out of the splitter
and off the mirrors is metal.  It stays clean w/o any work.

> use front-surface mirrors or prisms instead of second-surface mirrors? 

Front-surface mirrors.

> How adjustable is it? I did find the price of a new one and it is 
> ghastly!

Not adjustable at all, and is substantially smaller physically.  It's
also easy to keep "straight" and easy to "aim/focus".  In my experience
anyway.

> 
> It does look like I'm going to get my big toe wet with a low-end beam 
> splitter!

I'd strongly suggest a realist or a Kodak stereo camera, both of which 
can sometimes be bought for under a hundred dollars. 

Good beamsplitters have a niche (expecially if one has "the 2D stuff" 
already when talking in financial terms) to fill, but it's very small.  
When used on a SLR with a vertical flying shutter (as my Pentax SLR has) 
one can use very fast shutters on a sunny day -- much faster than the
fastest speed on typical 50's cameras.  And sometimes one will want
that much faster shutter, even if not terribly often.  Of course one
could use an RBT instead, or a well-synchronized pair of SLR's but
those options are either very expensive or big/heavy or both.

For getting your feet wet, get a Kodak or Realist and use 
a $3 Reel-3D viewer if you want to keep the "whole thing" under $100.

You WILL like it.  :-)

Mike K.


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